Diagnosing Mortons Neuroma

by elizwintringham

Overview

Morton’s neuroma is an enlarged nerve that usually occurs in the third interspace, which is between the third and fourth toes. To understand Morton’s neuroma further, it may be helpful to look at the anatomy of the foot. Problems often develop in the third interspace because part of the lateral plantar nerve combines with part of the medial plantar nerve here. When the two nerves combine, they are typically larger in diameter than those going to the other toes. Also, the nerve lies in subcutaneous tissue, just above the fat pad of the foot, close to an artery and vein. Above the nerve is a structure called the deep transverse metatarsal ligament. This ligament is very strong, holds the metatarsal bones together, and creates the ceiling of the nerve compartment. With each step, the ground pushes up on the enlarged nerve and the deep transverse metatarsal ligament pushes down. This causes compression in a confined space.

Causes

In many cases, a neuroma may develop as a result of excessive loading on the front of the foot. Sometimes, a patient?s anatomic alignment in the forefoot contributes to the overload. There may be some cases where the neuroma develops spontaneously, for no obvious reason. However, once the nerve is irritated, pressure from walking, and from the adjacent bony prominences (metatarsal heads), as well as from the intermetatarsal ligament that binds the heads together, all may contribute to persistent pain. Repetitive pressure on the nerve causes localized injury with resulting scarring and fibrosis of the nerve. This leads to symptoms in the distribution of the nerve.

Symptoms

Neuroma patients occasionally complain of a ?pins and needles? sensation that spreads through their feet, or of a feeling akin to hitting their ?funny bone.? The sensation may be described as similar to an electric shock. Some patients also say that these symptoms, as well as those listed above, will come and go, depending on what they are wearing on their feet, the activity they are doing, or on other external factors.

Diagnosis

Your health care provider can usually diagnose this problem by examining your foot. A foot x-ray may be done to rule out bone problems. MRI or ultrasound can successfully diagnose the condition. Nerve testing (electromyography) cannot diagnose Morton neuroma. But it may be used to rule out conditions that cause similar symptoms. Blood tests may be done to check for inflammation-related conditions, including certain forms of arthritis.

Non Surgical Treatment

You may be able to treat this problem at home. Avoid wearing tight, pointy, or high-heeled shoes. Choose well-fitted shoes with plenty of room for your toes. Put ice or a cold pack on the area for 10 to 15 minutes at a time. Put a thin cloth between the ice and your skin. Take anti-inflammatory medicines to reduce pain and swelling. These include ibuprofen (such as Advil or Motrin) and naproxen (such as Aleve). Rest your feet when you can. Reduce activities that put pressure on the toes, such as racquet sports or running. Try massaging your foot to relax the muscles around the nerve. If these steps do not relieve your symptoms, your doctor may have you use special pads or devices that spread the toes to keep them from squeezing the nerve. In some cases, a doctor may give a steroid shot to reduce swelling and pain. If these treatments do not help, your doctor may suggest surgery.

Surgical Treatment

Should the problem have progressed beyond the point where these measures are sufficient, the podiatric professional may recommend surgery. This procedure involves excision of the involved nerve mass. This will relieve the pain. Many patients report permanent numbness in the spot formerly affected by the neuroma, but prefer it to the pain. Most surgeries are successful; unfortunately, there are cases where the patient suffers another neuroma, sometimes in or near the same spot as before. A podiatric professional can explain the statistics of recurrence in various cases. If you suspect a neuroma, don?t wait for it to get better on its own. The earlier the diagnosis, the higher the likelihood that it can be treated with conservative measures. Don?t think that foot pain of any kind is inevitable, either, even if it runs in your family.

Prevention

Wearing proper footwear that minimizes compression of the forefoot can help to prevent the development of and aggravation of a Morton’s neuroma.